In conventional practice, there have been air conditioning apparatuses which have an outdoor heat exchanger composed of a heat exchanger in which flat perforated tubes are used as heat transfer tubes, and which perform an air-warming operation, as shown in Japanese Laid-open Patent Application No. 2012-163328. Specifically, such an air conditioning apparatus has a refrigerant circuit configured by connecting a compressor, an outdoor heat exchanger composed of a heat exchanger in which flat perforated tubes are used as heat transfer tubes, an expansion valve, and an indoor heat exchanger. Such an air conditioning apparatus is designed to perform an air-warming operation for warming air in a room by causing refrigerant to circulate through the compressor, the indoor heat exchanger, the expansion valve, and the outdoor heat exchanger in the stated order.